Mexico's Supreme Court has ruled a former president can face trial on genocide charges in connection with the deaths of protesters in 1971.

The court voted 3-2 Wednesday in the case on Luis Echeverria, saying a 30-year time limit for prosecuting him on charges has not expired. The case now returns to a lower court, which will begin reviewing evidence.

A 2002 law canceled the 30-year statute of limitations on genocide. But earlier this year, the five-member Supreme Court agreed with a lower court ruling that the law is not retroactive.

Mr. Echeverria, who served as Mexico's president from 1970 to 1976, has been accused of directing an attack on student demonstrators in 1971. Prosecutors say he ordered paramilitary forces to fire on the protesters, killing at least 11 people.